Core i5-750 system - moderate overclocking at 3.4GHz - cool and low power PC (last update 2010.04.28 - I will update this page if I will change anything)

This guide is for the ones who like to bring i5-750 closer to it's "true potential" without any risk for their components on the long therm. I am writing this based only on my personal experience with my components. After a lot of searching trial and testing, I managed to SAFELY overclock my system to 3.4GHz, keeping very low voltages and temperatures. This is a system designed to run on hot ambient up to 40ÂºC.

Why 3.4GHz? Because:
ï€­ 3.4GHz over 2.66GHz default is a decent overclock of roughly 30% (27.82%) and it is more then enough for all my needs. I will see no benefits to run a 4GHz rocket, my games would not run much more faster and my work won't be done essentially quicker.
ï€­ I want to be completely on the safe side, I don't like fried CPU's.
ï€­ Keeping low voltages means less heat and less stress on components that leads to longer life; I intend to keep my computer a very long time.
ï€­ Power consumption is a LOT lower with all power saving features enabled. At 4 GHz you need to disable them.

The noise level is very low from the three 12cm fans that came with Lian-Li case, and the CPU fan donâ€™t even counts. The fan from video card is audible only in 3D applications and the loudest components of the system are the three HDDâ€™s. Overall the system is fairly quiet and under the desk where I keep it is totally not disturbing.

BIOS Setup: J36_170x20
It took me a lot to understand that I have to enter MANUALLY all default values on BIOS, because on Gigabyte motherboards [AUTO] means really weird things (for example Vtt voltage left on AUTO was set by BIOS to almost 1.4v !!! when the default value is 1.100v and maximum specified by Intel is 1.21v). I am not sure about the other manufacturers but I would recommend to all Gigabyte users to write the default values manually on BIOS to protect their components on the long therm.
UPDATE: Looks like with the latest bios update, namely F8C (motherboard_bios_ga-p55-ud3_f8c.exe) these issues were corrected by Gigabyte. However, I still prefer to set my options manually rather then trusting AUTO.

o BIOS update using QFLASH and 1Gb USB stick. I noticed USB stick of 4Gb (FAT32 same as stick of 1gb) can't be detected by QFlash as a valid drive.

o TurboBoost deactivated from BIOS since bumping the multiplier to x24 at a frequency of 170x24=4080 MHz, is a sure crash at these low voltages, I donâ€™t even want to test that. All power saving features are explicitly ENABLED.
However if you are willing to increase Vcore to make it stable, TurboBoost is possible but I do not recommended it.

o System Memory Multiplier set at 8. This allow rising BCLK to 170 while keeping the memory frequency at only 1360 MHz at 7-7-7-20 timings. This allow me to set Performance Enhance on TURBO without causing instability. This apparently have an effect on Round Trip Latency (RTL) parameter and in my case the difference was clearly measurable in all windows applications. I pondered a lot between setting RAM at 1600 MHz with 8-8-8-20 and Performance Enhance on STANDARD as many users on different forums recommend, and the above settings. I underline again: RAM at 1360 MHz at 7-7-7-20 timings with Performance Enhance on TURBO -> windows "feel" much faster and everything is moving smoothly compared with setting RAM at 1600 MHz with 8-8-8-20 and Performance Enhance on STANDARD.
More about RTL here: http://www.anandtech.com/show/2869/6

- CPU-Z and Gigabyte Easy Tune 6 reports (CPU on idle and full load with Prime95)

- CPU TEMPERATURES (recorded after 23 minutes of INTEL BURNTEST - ambient temp = 22ÂºC)
o idle (170x9=1530MHz) = 31ÂºC (the highest core)
o full load (170x20=3400MHz) = 60ÂºC (60,58,58,58 for each core after 23 min. of IntelBurnTest at Maximum stress level)
o Note1: INTEL BURNTEST is the most stressful test for PC and in real programs you canâ€™t get temps this high even if you are using CPU at full load for hours.
o Note2: With this computer at 3.8GHz the speed (Gigaflops) on IntelBurnTest was 53? GFlops but the CPU temperature hit over 80ÂºC and power consumption increased to 310W. This is not for me, thank you very much.

- TEST7 = LONG TIME STABILITY TEST USING VARIOUS APLICATIONS AND MULTITASKING.
A long time stability test is needed for LGA 1156 platforms, as were seen computers fully stable that pass all stress tests flawlessly and then crash at random. This seems to happen because of a too low VTT - V Core voltages on overclocking. Since I tried to keep voltages (and temperatures) to a minimum for my modest overclock, this test is perhaps the most important indication that the computer is FULLY STABLE.
Playing different games for several hours on different days => no crash, all stable, 0 errors, PASSED

Some of the common i5-750 overclocking multipliers. Voltages are only for reference and potentially dangerous; DRAM voltage to be applied depend of your RAM modules. If you experience crashes it means the timings of the RAM are too tight or voltages must be increased further (possible to 1.50000 CPU Vcore and 1.45 VTT = on your own risk! Be aware that high voltages applied for extended period of time lead to accelerated component degradation and even burning!). If you get memory errors you need to relax the timings. I used in the past 7-7-7-20 for 166BCLK x 20CPU Vcore = 3320MHz CPU clock, at memory frequency = 1328MHz, and 8-8-8-20, 8-8-8-24, 9-9-9-24 for others.
CPU Vcore lowered to = 1.09375 and Vtt = 1.170. All perfect stable.

For case cooling i used 3 12cm fans that came with Lian Li case (+ one 12 cm fan from PSU if you want to count that).
For CPU I used the default 8 cm fan of the Scythe NINJA MINI (exit) + one AMD fan from an older system of 7 cm or maybe less (in).

One problem arose from the RAM modules that blocked the 8Cm fan to be installed in front of the heatsink, so, I installed it on the rear while in front right over a RAM module I placed the smaller AMD fan (in). Both fans have variable speed so, the noise is not too loud. I am sure these two can be easily replaced with one or two quiet fans.

The GPU is indeed louder when is used at 100% but on idle the noise is imperceptible. Some noise can be clearly heard from HDD's when they are heavy used, so the system overall is acceptable loud for me.

You have a point Steve, but the temperatures are calibrated right, I used for calibration HW Monitor program and Easy Tune 6 (that came with Gigabyte board) and they both report same values. To be sure I used in a higher overclock the beeping at 70 gr C option from BIOS, and right when my sensors from Windows reached 70 gr C, the overheating alarm set in BIOS started to beep, so I guess they are calibrated right. Only Coretemp utility had to be calibrated exactly at -10 gr C to match the other reported values of HWMonitor and Easy Tune 6.

flyingsherpa wrote:

I can't believe you posted that many pics, yet didn't include any of the completed system

Haha, you are absolutely right. I shall take some as soon I will have a lil time

I see you use Kingston ram. Is there a particular reason you use that brand? I am also considering Kingston because they are the 'brand' for memory. I don't plan to overclock my i7 860. I wondering which of these are good for me? What is XMP?

I decided to use Kingston mem. because I read some favorable reviews about them on different forums and because it was the cheapest good brand memory i found.

XMP (Xtrem Memory Profile) is a predefined overclocked profile embedded on the memory. When you set XMP on BIOS the memory is automatically overclocked at settings recommended by the producer. I choose to not use it even if my memory support it because I decided that is better to overclock the CPU with no risk at all and have better timings for memory (currently 7-7-7-20). The performance increase is a lot higher then if I only used XMP.

Good memory for you depends of your preference and budget. I would recommend some on the 1600MHz range, maybe you will want to overclock it a little later, this was my choice and I am happy with it. If you plan to overclock (CPU+MEM) like mad, go for the highest 2133MHz, but since you already said you are not into the overclocking, it really don't matter, you can just pick up the cheapest.

You have a point Steve, but the temperatures are calibrated right, I used for calibration HW Monitor program and Easy Tune 6 (that came with Gigabyte board) and they both report same values. To be sure I used in a higher overclock the beeping at 70 gr C option from BIOS, and right when my sensors from Windows reached 70 gr C, the overheating alarm set in BIOS started to beep, so I guess they are calibrated right. Only Coretemp utility had to be calibrated exactly at -10 gr C to match the other reported values of HWMonitor and Easy Tune 6.

Unless the laws of physics have been altered in your home, something has to give. Because, if your numbers hold true, when you turn your PC from idle to off, the core temps will go UP to meet ambient temp.

So, maybe what you are reporting as ambient temp is really some other monitored temp, like the mobo temp and not your room temp?

By definition, unless you are using refrigeration, ambient has to be the lowest reported temperature. Otherwise, you are absorbing heat and not generating heat.

You are right again Steve. I was looking on the BIOS at startup and the reported temps (on idle of course) are around 25 - 30 C, then in Windows are reported the same WHEN THE CPU IS SET AT X20 MULTIPLIER. I can only think that entering in a power save state like X9 multiplier, mess somehow the temp sensors, I don't understand how, since the temps in full load matches the ones in BIOS.

You can see in this screenshot the temps monitored with Core Temp (on taskbar) and with Easy Tune 6 (the utility provided by Gigabyte with the mobo), when at that time the ambient temperature was 24 C. Also the system temp is reported as 32 by the same Easy Tune 6... strange.

Haha, you got me, I am not in London. This remind me of that old joke...
A Frenchman and an Englishman meet on a tavern. After two months in London the French complains furious: "I have had enough, mist, mist and mist again, in this country is only mist!" The Englishman hurt in it's patriotic pride reply annoyed: "Of course not! When is raining is never mist..."

I will try to get those system photos a.s.a.p. but that means I need to shut down the comp. and I can't do that now... is running stright of almost 5 days already...

Thanks for the realtemp ideea, I will try it right away ....
...... several minutes later .....
I guess you were right guys, realtemp reported values 10 G higher I think I shall belive it instead of EasyTune and HWMonitor ... still is hard to believe that Gigabyte provided a tool that shows temperatures 10 G lower then the real ones I adjusted core temp offset to 0 and now it reports the same values as realtemp.

Idle

Load

After 45 mins. of Prime95 the temperature stabilized at 62G Thank you very much.

After I did some research on net I think I need to edit the first post again. It looks like RealTemp and CoreTemp are right and EasyTune6 is indeed wrong and this problem seems really common with this utility.

wazza300 Senior Member on some other forum said: et6 takes temps from the motherboard sensors and the heatsink, realtemp takes temps from the cpu core sensors inside the chip itself hence core temp, always go off the coretemp as its the part that gets hottest before it gets cooled by the heatsink and fan

Rather than a static overclock, you might try one with all of the turbo, speed step and C states enabled. Just set Vcore to "Normal". that will give you stock voltage which is sure to work at a bclk of 146. You probably should make sure LLC is disabled for this one. For more performance, try 160. Use a +.0125 DVID offset, if you need it. This latter setting will do 3660 Mhz on 4 cores and 3480 Mhz on one or two cores. These should be compatible with quiet cooling, although worst case core temperatures will be +45C over ambient with the Minja. I have also had good luck with a static overclock of 173 bclk and Vcore of 1.16875 (bios) with LLC enabled. All of this on a Gigabyte GA-P55-UD2.

Naw, it's just more in line with what's expected. Remember, a lot of the tests you were running are stress tests - conditions that you'll never see in real life apps.

Unfortunately for video encoding and other image and video rendering stuff I am working with, the CPU will need to do just that, 100% load sometimes for several days in a row.

diver wrote:

Rather than a static overclock, you might try one with all of the turbo, speed step and C states enabled. Just set Vcore to "Normal". that will give you stock voltage which is sure to work at a bclk of 146. You probably should make sure LLC is disabled for this one. For more performance, try 160.

I already tried that, is working but the power consumption and especially the temperatures are rising to a level I don't feel comfortable. I will rather stay with a cool and quiet machine overclocked moderately for everyday use in hot environment.

----------
Also, I lowered the memory voltage a little bit and the temperature in full load decreased with 2C on the second test to 62C. Memory was still fully stable, maybe I can try to lower it even more.
I am planning to take today some photos of the system to post them here.

I started to think at this myself, I had difficulty to mount ninja because of the Intel type pins that kept slipping. Those push pins are a pain. Maybe i should remove it and try to mount it again.

Bolt-thru kit for the Ninja? I didn't know that such thing exist, i just used what was in the package.

Yes, I did run Prime95 for one night (6h) and other night Memtest in 4 instances in same time to bring CPU at 100%. The max temps were the ones reported - from idle at 32C - to max full load 64C (after the new measurements with RealTemp).

About Catalyst, yes I use it, when I don't use video acceleration the GPU is silent, when I do I don't care about the noise anyway. I usually want the cooler on AUTO.

Here are finally some photos with my system:
[EDIT on 2010.02.01: I CHANGED THE CPU COOLER FAN, LOOK ON THE FIRST POST FOR THE UPDATED PHOTOS]

Bolt-thru kit for the Ninja? I didn't know that such thing exist, i just used what was in the package.

Yes, I did run Prime95 for one night (6h) and other night Memtest in 4 instances in same time to bring CPU at 100%. The max temps were the ones reported - from idle at 32C - to max full load 64C (after the new measurements with RealTemp).

I used a backplate retention kit with my Ninja on a socket 775. Removed the push pins and replaced them with the spring loaded bolts in the kit + the backplate. It improved my core temps by 5C. Perhaps one of the socket 1156 retention kitswould work with your Mini Ninja.

Regarding apps and temps. I think we are missing each others points. I was wondering two separate things:

1) Have you tried testing the CPU temps as above while running stock speeds to see how much impact the OC'ing is having on temps?

2) Have you tried measuring the temps when running the actual video encoding/etc. apps instead of these stress tests? (At stock and at OC) Very few apps ever approach the same level of CPU stressing as running Prime95, Orthos, etc. Your apps may run 10C cooler making all of this worry moot.

1) Have you tried testing the CPU temps as above while running stock speeds to see how much impact the OC'ing is having on temps?

2) Have you tried measuring the temps when running the actual video encoding/etc. apps?

About a bolt through kit - I will definitely look for something like this, thank you guys.

1. No, I never tested it at stock speeds because I had some issues with the PSU crackling noise when running at stock. But I did test it at a higher overclock of 3800MHz and the temperatures were a disaster, take a look here I stopped it because the temps kept rising:

2. Yes, the temperature on video encoding and rendering when the CPU is used 100% was one C lower then the Prime95 temp, so, no big difference at all.

ntavlas wrote:

1. "Have you tried further reducing cpu voltage? Or are you out of headroom?"

2. "I don`t think 62 is unsafe even if it`s sustained for long periods of time"

1. Out of headroom, when I try to lower it even more it looks stable at first, but after a random amount of time, sometimes after a day, it gets a windows crash even if tests are successful. However crash never happen with CPU Vcore = 1.13125V, so I guess this is the limit.

2. It is too hot for an ambient temp of 25C, sometimes the ambient can rise as high as 35 - 38C... so, if we are adding 10-13C...

----------------------------------------------------------
Other thing: I decreased DRAM voltage to 1.500V and the system seems still fully stable. The temp decreased 1C as well. Looks like this Kingston memory needs the specified voltage of 1.65 only for 1600MHz clock speed or higher, I noticed that compared to [email protected], at [email protected] the temperature of the mem. heat-sinks lowered dramatically, they are almost cold now.
----------------------------------------------------------
I am very grateful for your advices, guys, please keep posting if you can

IMPORTANT! I changed the first post of this thread in order to reflect the latest hardware and configuration changes I made to my system, including the updated tests, voltages and temperature readings.

Concerned about the high temps I decided to reinstall the CPU cooler. So, I removed the motherboard and I discovered that one of the Intel plastic push-pins jumped from itâ€™s place. Grrr. I reapplied a very even and thin layer of compound Arctic Silver Ceramique and carefully reinstalled the cooler. This time everything went smoothly and I changed the order of the fans too, removing the AMD fan. Now is much better, temperatures never go over 60C at a 25C ambient.

[This is the old thread posted on 2010.02.01. I updated the first thread of this post in order to reflect the latest configuration changes. Please read that one. I kept this as reference only. Replaced thumbnails with links for faster loading]

Core i5-750 system - mild overclocking - cool and low power PC

I just built an i5-750 based system and after a lot of searching I managed to overclock it a little without increasing voltages and keeping temperatures as low I can. This is a system designed to run on hot ambient up to 40ÂºC. Since it was done anyway I thought to share it with everyone, maybe someone will find these indications useful. I am not an experienced system builder, so if you find anything out of place with this built or if you have any comments please feel free to post replays.

The noise level is very low, from the three 12cm fans that came with Lian-Li case, and the CPU fan donâ€™t even counts. The fan from video card is audible only in 3D applications and the loudest components of the system are the three HDDâ€™s. Overall the system is fairly quiet and under the desk where I keep it is totally not disturbing.

- TEST3 = INTEL BURNTEST V.2.3
ï‚« Standard 1024Mb, 3 times => 0 errors PASSED
ï‚« Maximum 3259Mb, 10 times => 0 errors PASSED (1323 sec.)
http://www.postimage.org/image.php?v=Ts12RtEihttp://www.postimage.org/image.php?v=Ts12Rw8ro TEMPERATURES (ambient 26ÂºC): max. temp. on full load = 61ÂºC (59, 61, 59, 59 for each core after 22 min. of IntelBurn Test at Maximum stress level).
o Note1: that this is the most stressful test for PC and in real programs you canâ€™t get temps this high even if you are using CPU at full load for hours.
o Note2: With this computer at 3.8GHz the speed (Gigaflops) on IntelBurnTest was 53? GFlops but the CPU temperature hit over 80ÂºC and power consumption increased to 310W. This is not for me, thank you very much.

- TEST7 = LONG TIME STABILITY TEST USING VARIOUS APLICATIONS AND MULTITASKING (a long time stability test is needed for LGA 1156 platforms, as were seen computers fully stable that pass all stress tests flawlessly and then crash at random. This seems to happen because of a too low VTT - V Core voltages on overclocking. Since I tried to keep voltages (and temperatures) to a minimum for my modest overclock, this test is perhaps the most important indication that the computer is FULLY STABLE.
ï‚« Playing CIV4 for several hours on different days => no crash, all stable, 0 errors, PASSED
http://www.postimage.org/image.php?v=gxyCYJJ

~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~
Some of the common I5-750 overclocking multipliers. Voltages are only for reference and potentially dangerous; DRAM voltage depend of RAM modules. If you experience crashes it means the voltages must be increased further (possible to 1.50000 CPU Vcore and 1.45 VTT = on your own risk!). If you get memory errors you need to relax the timings. I have 7-7-7-20 for 166BCLK x 20CPU Vcore = 3320MHz CPU clock, at memory frequency = 1328MHz. I used 8-8-8-20, 8-8-8-24, 9-9-9-24 for the others.

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